Removed z-index version of the highlighter. Replaced some CSS3 animations with jQuery animations. Temporarily removed resize/reposition handling.

In order to better support complex z-index situations, I've removed the rounded-border highlight in favor of a highlight built out of top/left/right/bottom overlay elements. This effectively cuts a "hole" where the highlighted element is, making it so elements with z-index limitations can still be highlighted. Further removed CSS3 animations since browser support is iffy. Temporarily disabled the resize/reposition code since it was buggy.
Restored ability to reposition/resize upon window scroll or window resize.
Merge branch 'refs/heads/backdrop_refactor' into gh-pages